Garage door won’t close unless you hold the button

Sounds to me like the electric eye may be blocked or misaligned. If the receiver side doesn't see the signal from the transmitter side, it thinks there's something in the path of the door and raises the door again as soon as you take your finger off the button. That's where I'd start, checking the wiring and alignment and of course, making sure there's nothing blocking either side.

Here's the Chamberlain guide to troubleshooting your photo eyes. According to it, a malfunctioning photo eye exactly describes the issue you're seeing.

Troubleshoot Garage Door Safety Sensors that Are Off or Flicker